Unidirectional, multi-head fiber placement

ABSTRACT

An aircraft part manufacturing device for automated composite lay up includes a mandrel tool having a an interior mandrel surface that conforms to an outside mold line (OML) of a part: to be manufactured. One or more circular rings surround the mandrel and are attached to the mandrel. The circular rings rotate supported by bearings in a bearing cradle so that the mandrel rotates concentrically with the circular rings about an axis of rotation passing through the center of the circular rings. Multiple composite material delivery heads simultaneously deliver material directly to the outside mold line on the interior mandrel surface while the mandrel is rotated. A cantilever supported gantry beam supports the material delivery heads inside the interior mandrel surface. A connecting mechanism connects the material delivery heads to the gantry beam and provides motion of the material delivery heads relative to the interior mandrel surface.

BACKGROUND OF THE INVENTION

The present invention generally relates to fabrication of largecomposite structures and, more particularly, to automated compositelay-up of large aircraft fuselage sections.

The structural performance advantages of composites, such as carbonfiber epoxy and graphite bismaleimide (BMI) materials, are widely knownin the aerospace industry. Aircraft designers have been attracted tocomposites because of their superior stiffness, strength, and radarabsorbing capabilities, for example. As more advanced materials and awider variety of material forms have become available, aerospace usageof composites has increased. Automated tape layer technology hasdeveloped to become a widely used automated process for fabrication oflarge composite structures such as wing panels and empennage. Currenttape layer technology has been improved to offer flexibility in processcapabilities required for a wide variety of aerospace components. Asaerospace industry tape laying applications achieve material lay uprates, for example, that may help control the manufacturing cost oflarge composite structures, new and innovative applications for tapelayers may be defined, such as the automated tape lay-up of largeaircraft fuselage sections, for example, 15 to 20 feet in diameter.

Automated tape laying machines typically are gantry style machines thatmay have, for example, ten axes of movement with 5-axis movement on thegantry and 5-axis movement on the delivery head. A typical automatedtape layer consists of a gantry structure (parallel rails), a cross-feedbar that moves on precision ground ways, a ram bar that raises andlowers the material delivery head, and the material delivery head whichis attached to the lower end of the ram bar. Commercial tape layers aregenerally configured specifically for lay up of flat or mildly contouredlaminate applications using either flat tape laying machines (FTLM) orcontour tape laying machines (CTLM). On a gantry style tape layer,tooling (or a flat table) is commonly rolled under the gantry structure,secured to the floor, and the machine delivery head is then initializedto the lay up surface.

FIG. 1 provides an illustration of a typical tape laying machinematerial delivery head 100. Delivery heads for FTLM and CTLM machinesare basically the same configuration as that of delivery head 100 shownin FIG. 1. The delivery heads on commercial automated tape layers aretypically configured to accept material widths of 75 mm (3″), 150 mm(6″), and 300 mm (12″). Flat tape layers typically use material in 150mm (6″) and 300 mm (12″) widths. Contour tape layers typically usematerial in 75 mm (3″) and 150 mm (6″) widths. CTLM systems normally usethe 3″ or 6″ wide material when laying up off flat plane contoursurfaces. Material 102 for tape layers generally comes in large diameterspools. The tape material 102 has a backing paper 106, which must beextracted as the prepreg (resin pre-impregnated fiber) is applied to thetool surface 108. The spool of material typically is loaded into thedelivery head supply reel 104 and threaded through the upper tape guidechute and past the cutters 110. The material 102 then passes through thelower tape guides, under the segmented compaction shoe 112, and onto abacking paper take up reel 114. The backing paper is extracted and woundon a take up roller of paper take up reel 114. The delivery head 100makes contact with the tool surface 108 and the tape material 102 is“placed” onto the tool surface 108 with compaction pressure. The tapelaying machine typically lays tape on the tool surface 108 in a computerprogrammed path (course), cuts the material 102 at a precise locationand angle, lays out tail, lifts delivery head 100 off the tool surface108, retracts to the course start position, and begins laying the nextcourse. The delivery head 100 may have an optical tape flaw detectionsystem that signals the machine control to stop laying tape material 102when a flaw has been detected. The delivery head 100 also typically hasa heating system 116 that heats the prepreg materials to increase tacklevels for tape-to-tape adhesion. Heated tape temperatures generallyrange from 80 F to 110 F.

Fiber placement is a similar process in which individual prepreg fibers,called tows, are pulled off spools and fed through a fiber deliverysystem into a fiber placement head, which is similar to delivery head100 shown in FIG. 1. In the fiber placement head, tows may be collimatedinto a single fiber band and laminated onto a work surface, which can bemounted between a headstock and tailstock. When starting a fiber band orcourse, the individual tows are fed through the head and compacted ontoa surface—such as surface 108. As the course is being laid down, thehead 100 can cut or restart any of the individual tows. This permits thewidth of the fiber band to be increased or decreased in increments equalto one tow width. Adjusting the width of the fiber band eliminatesexcessive gaps or overlaps between adjacent courses. At the end of thecourse, the remaining tows may be cut to match the shape of the plyboundary. The head may then be positioned to the beginning of the nextcourse. During the placement of a course, each tow is dispensed at itsown speed, allowing each tow to independently conform to the surface 108of the part. Because of this, the fibers are not restricted to geodesicpaths. They can be steered to meet specified design goals. A rollingcompaction device, combined with heat for tack enhancement, laminatesthe tows onto the lay-up surface 108. This action of pressing tows ontothe work surface (or a previously laid ply) adheres the tows to thelay-up surface 108 and removes trapped air, minimizing the need forvacuum debulking. It also allows the fiber to be laid onto concavesurfaces.

A fiber placement head, like the tape laying head, may be provided withseveral axes of motion, using an arm mechanism, for example, and may becomputer numeric controlled. The axes of motion may be necessary to makesure the head 100 is normal to the surface 108 as the machine islaminating tows. The machine may also have a number of electronic fibertensioners, which may be mounted, for example, in an air conditionedcreel. These tensioners may provide individual tow payout and maintain aprecise tension. The head 100 may precisely dispense, cut, clamp, andrestart individual prepreg tows.

In the quest to automate the placement of composite materials at a highrate—to make the use of composites economical compared to conventionalmethods of fuselage fabrication—efforts have been focused at wrappingaround a male mandrel, i.e. tool. Today's composite, fiber materialplacement processes and equipment have used male mandrels exclusively,wrapping tape layers on the outside surface of the tool—such as toolsurface 108. One problem with this approach is that controlling theoutside surface of the part—such as a fuselage section—is not possiblewithout transferring the part to a female tool or clam shell typetooling.

Fuselage fabrication using composites also requires automated placementof composite materials at a rate high enough to make the use ofcomposites economical compared to conventional methods of fuselagefabrication. The manufacture of very large fuselage parts economically,for example, will require composite material lay down rates that aresignificantly faster than those typical in the prior art. Prior artprocesses such as tape laying and fiber placement are currently too slowto be economically viable to meet production rates on new large scaleaircraft programs, such as Boeing's 7E7. Tools and processes forautomated placement of composite materials are needed that greatlyincrease the lay down rates over the state of the art, and which willreduce the number of machines required for a large scale manufacturingprogram.

As can be seen, there is a need for fabrication of composite parts usingan automated lay-up machine that allows material placement to an outsidemold surface, from inside a tool, allowing greater control and accuracyforming the exterior surface of the part. Also, there is a need for anautomated lay-up machine that greatly increases the lay down rates,compared to the prior art, for economical composite fabrication of largediameter fuselage sections.

SUMMARY OF THE INVENTION

In one aspect of the present invention, a device for automated compositelay-up includes a tool having an axis of rotation. The tool includes amandrel with an outside mold surface of a part to be manufactured. Theoutside mold surface is on the inside of the mandrel. The device alsoincludes a circular ring surrounding the tool and the mandrel andconcentric with the axis of rotation wherein the tool is rotated aboutthe axis of rotation and composite material is delivered directly to theoutside mold surface inside of the mandrel. The device includes a gantrybeam disposed to access the inside of the mandrel; and multiple materialdelivery heads supported by the gantry beam. The gantry beam providesfor movement of the multiple material delivery heads relative to theoutside mold surface; and at least one of the multiple material deliveryheads has an individually adjustable position relative to the outsidemold surface.

In another aspect of the present invention, a device for automatedcomposite lay-up includes a tool having a mandrel. The mandrel has aninterior mandrel surface that conforms to an outside mold line of apart. At least one circular ring is attached to the tool, and thecircular ring surrounds the tool and the mandrel. A bearing contacts thecircular ring, and the circular ring rotates supported by the bearing sothat the tool and the mandrel rotate concentrically with the circularring about an axis of rotation passing through the center of thecircular ring. A gantry beam is disposed to access the inside of themandrel; and multiple material delivery heads are supported by thegantry beam. The gantry beam provides for movement of the multiplematerial delivery heads relative to the interior mandrel surface; and atleast one of the multiple material delivery heads has an individuallyadjustable position relative to the interior mandrel surface.

In still another aspect of the present invention, a device for automatedcomposite lay-up includes a tool having a mandrel and a circular ringhaving a center. The mandrel has an interior mandrel surface thatconforms to an outside mold line of a part. The circular ring surroundsthe mandrel and is attached to the mandrel. A bearing cradle includes anumber of bearings, and at least one bearing contacts the circular ring.The bearing cradle supports the weight of the tool through the bearings.The circular ring rotates supported by the bearings so that the mandrelrotates concentrically with the circular ring about an axis of rotationpassing through the center of the circular ring. A gantry beam isdisposed to access the inside of the mandrel; and multiple materialdelivery heads are supported inside the mandrel by the gantry beam. Thegantry beam provides for movement of the multiple material deliveryheads relative to the interior mandrel surface; and at least one of themultiple material delivery heads has an individually adjustable positionrelative to the interior mandrel surface.

In yet another aspect of the present invention, an aircraft partmanufacturing device for automated composite lay up includes a toolhaving a mandrel and a circular ring having a center. The mandrel has aninterior mandrel surface that conforms to an outside mold line of apart. The circular ring surrounds the mandrel and is attached to themandrel. A bearing cradle includes a number of bearings, and at leastone bearing contacts the circular ring. The bearing cradle supports theweight of the tool through the bearings. The circular ring rotatessupported by the bearings so that the mandrel rotates concentricallywith the circular ring about an axis of rotation passing through thecenter of the circular ring, and the bearing cradle is moveable. Amultiple number of material delivery heads deliver composite materialdirectly to the outside mold line on the interior mandrel surface. Agantry beam is cantilever supported, and the gantry beam is moveablerelative to the tool. The gantry beam supports the multiple materialdelivery heads inside the interior mandrel surface of the mandrel. Aconnecting mechanism connects at least one of the multiple materialdelivery heads to the gantry beam, so that: the connecting mechanismprovides axial motion of the at least one material delivery headrelative to the interior mandrel surface; the connecting mechanismprovides motion of the at least one material delivery head relative tothe interior mandrel surface in a direction normal to the interiormandrel surface; and the connecting mechanism provides rotation of theat least one material delivery head relative to the interior mandrelsurface about an axis normal to the interior mandrel surface.

In a further aspect of the present invention, an aircraft partmanufacturing device for automated composite lay up includes means forrotating a mandrel about a axis of rotation. The mandrel has an outsidemold surface on the inside of the mandrel. The device also includesmeans for supporting a multiple number of material delivery heads insidethe mandrel and simultaneously delivering composite material from themultiple material delivery heads at the outside mold surface.

In a still further aspect of the present invention, a method isdisclosed for automated composite lay up on an interior mandrel surfaceof a tool having an axis of rotation. The mandrel has an outside moldsurface on the inside of the mandrel. The method includes rotating themandrel about a axis of rotation; supporting a multiple number ofmaterial delivery heads interior to the outside mold surface; andplacing a composite fiber material inside the mandrel onto the outsidemold surface simultaneously from the multiple material delivery heads.

These and other features, aspects and advantages of the presentinvention will become better understood with reference to the followingdrawings, description and claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram of a typical tape laying machine material deliveryhead, as known in the art;

FIG. 2 is a perspective illustration of an aircraft part manufacturingdevice for automated composite lay up, according to one embodiment ofthe present invention;

FIG. 3 is a perspective illustration of an aircraft part manufacturingdevice for automated composite lay up, according to another embodimentof the present invention; and

FIG. 4 is a perspective illustration of an aircraft part manufacturingdevice for automated composite lay up, according to yet anotherembodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

The following detailed description is of the best currently contemplatedmodes of carrying out the invention. The description is not to be takenin a limiting sense, but is made merely for the purpose of illustratingthe general principles of the invention, since the scope of theinvention is best defined by the appended claims.

Broadly, one embodiment of the present invention provides fabrication ofparts made of composite materials, which may be used, for example, inthe manufacture of commercial and military aircraft. In one embodiment,an automated lay-up machine allows material placement directly to anoutside mold surface and eliminates prior art techniques of expansionand transfer of the part to another tool, allowing greater control andaccuracy over the prior art in forming the exterior surface of the partand resulting in less defects and higher surface quality compared toparts fabricated according to the prior art. In one embodiment, thepresent invention enables the automated lay down and compaction of largequantities of high performance composite materials onto largecylindrical shaped mandrels (typically greater than 15 feet in diameter)at very high rates compared to the prior art. In one embodiment, anautomated lay-up machine may be ideally suited for composite fabricationof fuselage sections having large diameter, for example, from 15 to 20feet.

In one embodiment, multiple automated lay-up machines (material deliveryheads) may place the composite materials directly to the outside moldsurface from inside the tool. Such operation would be difficult forprior art fuselage fabrications—such as Premier I and Horizon businessjets made by Raytheon, Inc.—because of the relatively small diameter ofthe business jet fuselage, which may necessitate conventional outsidelay-up using a male mandrel. Automated tape and fiber lay-up equipmentand gantry beam could easily fit, however, within a large commercialaircraft fuselage, for which the diameter could reach in excess of 20feet. In addition, alternative embodiments of the present inventionallow for orientation of the mold or lay-up mandrel at any angle orattitude, for example, horizontal, vertical, or tilted, that mayfacilitate the fabrication of long fuselage sections that may be in therange, for example, of 30 to 40 feet or more in length. In addition, themultiple delivery heads of one embodiment allow for fast material buildup from outside mold line (OML) to inside mold line (IML) at rates thatare economical for the production of large fuselage sections.

Because use of the tool of one embodiment eliminates prior arttechniques of building on a male mandrel and transferring to a femalemandrel tool, the problems inherent in such prior art techniques may beavoided. For example, using prior art tools and processes, graphite orother fibers wrapped in the hoop direction around a fuselage do notallow the composite to expand out and conform properly to the femaletool, creating difficulty for expanding the part, so that the part doesnot make proper contact with, or conform to the female tool. Parts madeusing an embodiment of the present invention may be expected to be ofhigher quality and have fewer exterior surface defects because the priorart need to expand the part has been eliminated, eliminating thoseproblems associated with the prior art fabrication tools and techniques.

Referring now to the figures, wherein like items are referenced with thesame numerals, and in particular, referring to FIG. 2, an aircraft partmanufacturing device 200 for automated composite lay up is illustratedin accordance with one embodiment. Device 200 may include a tool 202that may have an axis of rotation 204. Tool 202 may be situated so thataxis of rotation 204 is placed at any desirable angle or attituderelative to horizontal. The example embodiment illustrated in FIG. 2shows a horizontal configuration of device 200 in which the attitude ofaxis of rotation 204 may be horizontal or nearly horizontal, as shown inFIG. 2, or also may be tilted. Other configurations and attitudes,however, are contemplated. For example, FIG. 6 shows one possibleconfiguration in which axis of rotation 204 may be placed vertically orat attitudes closer to vertical than may be practical with theconfiguration shown in FIG. 2. Tool 202 may have a mandrel 206, whichmay be approximately cylindrical, or symmetrical about axis of rotation204. Mandrel 206 is shown in cut away view in FIGS. 2 through 4 to aidviewing other parts of the drawings. The inside of mandrel 206 may havean interior mandrel surface 208, which may conform to an outside moldsurface or an outside mold line (OML) of an aircraft part to bemanufactured. Interior mandrel surface 208 may also be referred to asthe “outside mold surface” or “OML”. Tool 202 may include stiffeners 210that provide extra strength and stiffness to support outside moldsurface, i.e., interior mandrel surface 208, of mandrel 206 while addinga minimal amount of extra weight to tool 202.

Device 200 may include circular rings 212 and 214, which may be integralwith tool 202 or may be attached to tool 202. Stiffeners 210 may alsoattach to circular rings 212 and 214 to provide extra integrity ofcircular rings 212 and 214 with tool 202. Circular rings 212 and 214 mayattach to stiffeners 210 as well as to mandrel 206 to provide extrastrength and rigidity of the attachment of circular rings 212 and 214 tomandrel 206 of tool 202. Circular rings 212 and 214 may be in contactwith bearings 216, which may support rotation of tool 202 and mandrel206. Circular rings 212 and 214 may surround tool 202, and mandrel 206,and may be concentric with axis of rotation 204 so that rotation ofcircular rings 212 and 214 on bearings 216 rotates mandrel 206 about itsaxis of rotation 204. In other words, circular rings 212 and 214 rotatesupported by bearings 216 so that mandrel 206 rotates concentricallywith circular rings 212 and 214 about an axis of rotation 204 passingthrough the center of circular rings 212 and 214. Bearings 216 may beheld by a bearing cradle 218 that may support the weight of tool 202,including mandrel 206 and circular rings 212 and 214, through thebearings 216. Bearing cradle 218 may be moveable, for example, toprovide transport of tool 202 and the part being manufactured from onestage of a manufacturing process to another.

Device 200 may also include a gantry beam 220 disposed to access theinside of the mandrel 206. Gantry beam 220 may be cantilever supported,for example, by cantilever supports 222. Cantilever supports 222 may befitted with rollers 224. Gantry beam 220 may be supported as acantilever beam using rollers 224 so that gantry beam 220 is moveablerelative to tool 202. Gantry beam 220 may be further supported by a tailstock 226 so that gantry beam 220 becomes either fully supported as abeam between tail stock 226 and cantilever supports 222 or becomespartially cantilever supported by cantilever supports 222 and partiallysupported as a beam between tail stock 226 and cantilever supports 222.Tail stock 226 may, for example, also be fitted with rollers—such asrollers 224—or may otherwise be made to “telescope”—so that gantry beam220 remains moveable relative to tool 202 when tail stock 226 isconnected to gantry beam 220 for support. Tail stock 226 may beremovable from gantry beam 220 and moveable so that tool 202 may beremovable from gantry beam 220, for example, as tool 202 may be movedfrom one stage of a manufacturing process to another.

Device 200 may further include multiple composite material deliveryheads 228. Material delivery heads 228, for example, may be similar tomaterial delivery head 100, such as a flat tape laying machine, contourtape laying machine, or fiber placement head. Material delivery heads228, for example, may be adaptations of an existing delivery heads, suchas a tape laying or fiber placement heads, as needed to meet surfacecontour requirements, as the contour of interior mandrel surface 208 mayvary widely depending on the aircraft part which aircraft partmanufacturing device 200 is being used to manufacture. For example, tapelaying heads may be used for material delivery heads 228 when the tool202 and interior mandrel surface 208 cross sections remain mostlyconstant, as seen in FIG. 2. By the same token, fiber placement headsmay be more suitable for use for material delivery heads 228 when thecross sections of tool 202 and interior mandrel surface 208 changesignificantly along the length of the tool 202, for example.

The multiple material delivery heads 228 may be supported interior tothe interior mandrel surface 208 inside of mandrel 206, as shown in FIG.2, so that balanced pressure may be exerted by multiple materialdelivery heads 228 in opposing directions inside mandrel 206 to aid inthe delivery of composite material to interior mandrel surface 208.Composite material may be delivered simultaneously in multiple coursesdirectly to the outside mold line on the interior mandrel surface 208.For example, gantry beam 220 may support multiple material deliveryheads 228 inside interior mandrel surface 208 of mandrel 206, so thatcomposite material is delivered directly to the outside mold surface onthe inside of mandrel 206.

Device 200 may include one or more connecting mechanisms 232 that mayconnect one or more material delivery heads 228 to gantry beam 220.Connecting mechanism 232 may provide axial motion relative to interiormandrel surface 208, i.e., motion in a direction parallel to axis ofrotation 204, of one or more material delivery heads 228 along gantrybeam 220. Device 200 may also include arm mechanisms 234 that mayconnect each material delivery head 228 to gantry beam 220 or toconnecting mechanism 232. Arm mechanisms 234 may provide motion ofmaterial delivery heads 228 relative to the outside mold surface, i.e.,interior mandrel surface 208, of mandrel 206. Connecting mechanism 232and arm mechanisms 234 are further described below.

In operation, material delivery heads 228 may translate along the entirelength of the tool 202 while tool 202 rotates, allowing the materialdelivery heads 228 to simultaneously place material in multiple coursesover the entire tool surface, i.e., interior mandrel surface 208. Themultiple courses of composite material may be laid down in variouspatterns on interior mandrel surface 208 depending on the relativemotion between material delivery heads 228 and tool 202. Gantry beam 220may provide an axial motion of material delivery heads 228, for example,by movement of gantry beam 220 using rollers 224, as described above.Alternatively, gantry beam 220 may be supported at one end by tail stock226 during operation of material delivery heads 228, and connectingmechanism 232 may provide an axial motion of material delivery heads 228by moving material delivery heads 228 along gantry beam 220.

At the same time, tool 202 may or may not be rotated. For example, ifmaterial delivery heads 228 are held stationary while tool 202 isrotated, courses of composite material may be laid down in acircumferential, or hoop, direction on interior mandrel surface 208.Also for example, if material delivery heads 228 are moved axially whiletool 202 is held stationary courses of composite material may be laiddown in an axial direction on interior mandrel surface 208. If both themultiple material delivery heads 228 are moved axially while tool 202 isrotated, courses of composite material may be laid down in a helicalpattern, with the helix angle depending on the relative velocities ofmotion and rotation.

Material delivery heads 208 may be controlled in coordination with therotation of tool 202, mandrel 206, and interior mandrel surface 208, forexample, by using existing numerical control (NC) or computer numericalcontrol (CNC) programming software to control the material deliveryheads 208 and tool 202 simultaneously. For example, rotation of tool 202may be driven through bearings 216 using CNC control coordinated withCNC control of the material delivery heads 208.

Referring now to FIG. 3, an aircraft part manufacturing device 240 forautomated composite lay up is illustrated in accordance with anotherembodiment. Interior mandrel surface 208 of mandrel 206 of tool 202 mayhave a non-constant cross section. Mandrel 206 is shown in cut away viewin FIG. 3 to aid viewing other parts of the drawing. When mandrel 206has a non-constant cross section, circular ring 214 may have a differentthickness 244 than thickness 242 of circular ring 212. Thus, thethicknesses 242, 244 of circular rings 212, 214 may be used tocompensate for a mandrel 206 having non-constant cross sections so thatwhen circular rings 212 and 214 are rotated supported by bearings 216,mandrel 206 may rotate concentrically with circular rings 212 and 214about an axis of rotation 204 passing through the center of circularrings 212 and 214.

Device 240 may include one or more connecting mechanisms 232 that mayconnect material delivery head 228 to gantry beam 220. Material deliveryhead 228 may be a fiber placement head, for example, to aid in thelaying down of material on mandrel 206 when the contours of mandrel 206are more complex than a constant cross section mandrel. Connectingmechanism 232 may provide axial motion of multiple material deliveryheads 228 relative to interior mandrel surface 208 and may also providemotion of material delivery heads 228 along gantry beam 220 if gantrybeam 220 is held stationary during operation of material delivery head228, for example, using tail stocks such as tail stock 226 shown in FIG.2. Connecting mechanism 232 also may provide individual axialpositioning adjustment of each of multiple material delivery heads 228relative to interior mandrel surface 208, and independently of andrelative to the other material delivery heads 228.

Independent axial position adjustment would be useful, for example, whenplacing plies of material in the circumferential direction, or hoopdirection of the cylinder of tool 202. In this case, all, or some of theheads 228 might reposition themselves relative to each other axially,along the length of the tool 202, so that the bands, i.e., courses, ofmaterial placed would be adjacent to each other without overlap or gaps,when placed onto the tool 202 or interior mandrel surface 208.

Connecting mechanism 232 also may provide individual motion of each ofmaterial delivery heads 228 relative to interior mandrel surface 208 ina direction normal, i.e. perpendicular, to interior mandrel surface 208.Connecting mechanism 232 also may provide individual rotation of each ofmaterial delivery heads 228 relative to interior mandrel surface 208about an axis normal to interior mandrel surface 208.

Device 240 may also include arm mechanisms 234 that may connect materialdelivery heads 228 to gantry beam 220 or to connecting mechanism 232 asshown in FIG. 3. Arm mechanisms 234 may provide individual, i.e.,independent of the other material delivery heads 228, motion of eachmaterial delivery head 228 relative to interior mandrel surface 208 in adirection normal to interior mandrel surface 208. Arm mechanisms 234also may provide individual rotation of each material delivery head 228relative to interior mandrel surface 208 about an axis normal tointerior mandrel surface 208. Arm mechanisms 234 also may provideindividual motion or position adjustment of each material delivery head228 relative to interior mandrel surface 208 in an axial directionrelative to interior mandrel surface 208. Arm mechanisms 234 also mayprovide individual motion or position adjustment of material deliveryheads 228 relative to interior mandrel surface 208 in a circumferential,or hoop, direction relative to interior mandrel surface 208.

FIG. 4 illustrates another embodiment of an aircraft part manufacturingdevice 270. FIG. 4 shows material delivery head 228 laying a course 230of composite material to an OML at an interior mandrel surface 208 of amandrel 206 of a tool 202. Tool 202 may include a ring 212 supported onbearings. As shown in FIG. 4, material delivery head 228 may besupported above interior mandrel surface 208 by a gantry beam 220.Connecting mechanism 232 may provide axial motion and positioning ofmaterial delivery head 228 along gantry beam 220 and may support andconnect arm mechanism 234 to gantry beam 220. Arm mechanism 234, asdescribed above, may provide motion of material delivery head 228relative to interior mandrel surface 208 in a direction normal tointerior mandrel surface 208, i.e., up and down relative to interiormandrel surface 208 and at an oblique angle with respect to horizontalas seen in FIG. 4. Arm mechanism 234, as described above, may alsoprovide rotation of material delivery head 228 about an axis normal tointerior mandrel surface 208; motion in an axial direction relative tointerior mandrel surface 208; and motion in a circumferential, or hoop,direction relative to interior mandrel surface 208.

A method for automated composite lay up on an interior mandrelsurface—such as interior mandrel surface 208 of mandrel surface 206 oftool 202—may include rotating the mandrel about an axis of rotation—suchas axis of rotation 204—which may have any angle or attitude including,for example, horizontal, vertical, and tilted. The interior mandrelsurface may conform to the outside mold surface, or OML, of a part to bemanufactured. The method may also include supporting multiple, i.e., twoor more, composite material delivery heads—such as multiple materialdelivery heads 228, which may be composite tape laying machines or fiberplacement heads, for example. The method may include supporting themultiple composite material delivery heads interior to the interiormandrel surface inside the mandrel and placing composite fiber from themultiple material delivery heads simultaneously onto the interiormandrel surface, i.e., onto the outside mold surface of the part.

The method may also include rotationally supporting the mandrel on abearing in contact with a circular ring surrounding the mandrel—such asbearings 216 contacting circular rings 212 and 214 surrounding andsupporting mandrel 206. The method may include supporting the bearing ina bearing cradle and supporting the weight of the mandrel, the tool, andthe circular ring using the bearing cradle.

The method may also include supporting the multiple material deliveryheads from a gantry beam—such as gantry beam 220—and supporting one endof the gantry beam using a tail stock—such as tail stock 226. The methodmay include providing axial motion of the multiple material deliveryheads along the gantry beam, for example, by using a connectingmechanism such as connecting mechanism 232. The method may provide anindividual circumferential position adjustment of each of the materialdelivery heads in a hoop direction relative to the interior mandrelsurface, an individual axial position adjustment of each of the materialdelivery heads relative to the mandrel surface, individual motion ofeach of the material delivery heads in a direction normal to the mandrelsurface, and individual rotation of each of the material delivery headsabout an axis normal to the mandrel surface, for example, by usingmechanisms that connect the material delivery heads to the gantrybeam—such as connecting mechanism 232 and arm mechanisms 234.

It should be understood, of course, that the foregoing relates topreferred embodiments of the invention and that modifications may bemade without departing from the spirit and scope of the invention as setforth in the following claims.

1-26. (canceled)
 27. A method for automated composite lay up on an interior mandrel surface of a tool having an axis of rotation, comprising steps of: rotating a mandrel about the axis of rotation wherein said mandrel has an outside mold surface on the inside of said mandrel; supporting a plurality of material delivery heads interior to said outside mold surface; and placing a composite fiber material inside said mandrel onto said outside mold surface simultaneously from said plurality of material delivery heads.
 28. The method of claim 27 wherein said rotating step further comprises supporting said mandrel on a bearing in contact with a circular ring surrounding said mandrel.
 29. The method of claim 27 wherein said rotating step further comprises: supporting said mandrel on a bearing in contact with a circular ring surrounding said mandrel; and supporting said bearing in a bearing cradle so that said bearing cradle supports the weight of said mandrel, the tool, and said circular ring.
 30. The method of claim 27 wherein said supporting step further comprises: supporting said plurality of material delivery heads from a gantry beam; and providing axial motion of said plurality of material delivery heads.
 31. The method of claim 27 wherein said supporting step further comprises: providing motion of at least one of said plurality of material delivery heads relative to said outside mold surface in a direction normal to said outside mold surface; and providing rotation of said at least one material delivery head relative to said outside mold surface about an axis normal to said outside mold surface.
 32. The method of claim 27 wherein said supporting step further comprises: supporting said plurality of material delivery heads from a gantry beam; and supporting at least one end of said gantry beam using a tail stock. 